(a) Field of the Invention
The present invention relates to an EDM drill, and more particularly, to one comprised of an electrode tube changer and guide changer capable of replacing, and selecting an electrode tube and guide to achieve fully automated and continuous operation of hole discharge processing (drilling) on work pieces of different thickness and hole size.
(b) Description of the Prior Art
Please refer to FIG. 9.
EDM drilling: Chucking an electrode tube (P) on a spindle. Adjust a W-axis (W) on an X-axis (X) and a Y-axis (Y) to a starting position of a work piece. Move an electrode tube guide (G) of the W-axis (W) to where above the work piece at a proper height while allowing the electrode tube (P) pass through the guide (G). Activate a C-axis (C) to rotate the electrode tube (P) and mostly supply the dielectric fluid, and control a Z-axis (Z) movement according the condition between the electrode tube (P) and the work piece to drill a hole into the work piece by electrical-discharge power.
The prior art is observed with the following limitations: (1) It is difficult to automatically replace the electrode tube since the electrode tube practically gives no rigidity. For that reason, it prevents the use of a device like an ATC (Automatic Tool Changer) that is used by a machining center to chuck the electrode tube to the spindle today. (2) It prevents the automatic selection of a different guide size which is needed to hold different size of electrode in order to drill different size of hole.